Active drive mechanism with finite range of motion

ABSTRACT

Various exemplary drive apparatuses and associated methods are disclosed for driving an elongated member, e.g., a catheter, sheath, or guidewire. An exemplary drive apparatus may include a first component and a moveable component, each configured to selectively grip the elongated member. In some examples, the first and moveable components may each include a gripping device. The moveable component may be configured to selectively move axially and rotationally with respect to a support surface to effect axial movement and rotation movement, respectively, of the elongated member with respect to the support surface within a range of motion of the moveable component. The moveable component may be configured to move the elongated member across a predetermined movement having a magnitude greater than the range of motion.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/838,777, filed Mar. 15, 2013, and entitled “ACTIVE DRIVE MECHANISMWITH FINITE RANGE OF MOTION,” the entirety of which is hereinincorporated by reference for all purposes.

BACKGROUND

Robotic interventional systems and devices are well suited forperforming minimally invasive medical procedures as opposed toconventional techniques wherein the patient's body cavity is open topermit the surgeon's hands access to internal organs. However, advancesin technology have led to significant changes in the field of medicalsurgery such that less invasive surgical procedures, in particular,minimally invasive surgery (MIS), are increasingly popular.

MIS is generally defined as a surgery that is performed by entering thebody through the skin, a body cavity, or an anatomical opening utilizingsmall incisions rather than large, open incisions in the body. With MIS,it is possible to achieve less operative trauma for the patient, reducedhospitalization time, less pain and scarring, reduced incidence ofcomplications related to surgical trauma, lower costs, and a speedierrecovery.

Special medical equipment may be used to perform MIS procedures.Typically, a surgeon inserts small tubes or ports into a patient anduses endoscopes or laparoscopes having a fiber optic camera, lightsource, or miniaturized surgical instruments. Without a traditionallarge and invasive incision, the surgeon is not able to see directlyinto the patient. Thus, the video camera serves as the surgeon's eyes.The images of the interior of the body are transmitted to an externalvideo monitor to allow a surgeon to analyze the images, make adiagnosis, visually identify internal features, and perform surgicalprocedures based on the images presented on the monitor.

MIS devices and techniques have advanced to the point where an insertionand rolling motion of components of an elongated component such as acatheter instrument, e.g., a catheter sheath and associated guidewire,are generally controllable by selectively operating rollers or othermechanisms for generally gripping the component. Some known mechanismsuse gripping devices capable of infinite motion for insertion of acatheter, e.g., a roller, may require more complex catheter componentloading procedures, or may not be compatible with replaceable componentsadapted for a sterile operating environment.

Accordingly, there is a need in the art for systems and methods forinserting and rolling catheter components that address or solve theabove problems.

SUMMARY

Various exemplary drive apparatuses and associated methods are disclosedfor driving an elongated member, e.g., a catheter, sheath, or guidewire.An exemplary drive apparatus may include a first component and amoveable component, each configured to selectively grip the elongatedmember. In some examples, the first and moveable components may eachinclude a gripping device. The moveable component may be configured toselectively move axially and rotationally with respect to a supportsurface to effect axial movement and rotation movement, respectively, ofthe elongated member with respect to the support surface within a rangeof motion of the moveable component. The moveable component may beconfigured to move the elongated member across a predetermined movementhaving a magnitude greater than the range of motion.

BRIEF DESCRIPTION OF THE DRAWINGS

While the claims are not limited to the illustrated embodiments, anappreciation of various aspects is best gained through a discussion ofvarious examples thereof. Referring now to the drawings, illustrativeembodiments are shown in detail. Although the drawings represent theembodiments, the drawings are not necessarily to scale and certainfeatures may be exaggerated to better illustrate and explain aninnovative aspect of an embodiment. Further, the embodiments describedherein are not intended to be exhaustive or otherwise limiting orrestricting to the precise form and configuration shown in the drawingsand disclosed in the following detailed description. Exemplaryembodiments of the present invention are described in detail byreferring to the drawings as follows.

FIG. 1 is an illustration of a robotically controlled surgical system,according to one exemplary illustration;

FIG. 2 is an illustration of an exemplary catheter assembly of thesurgical system of FIG. 1;

FIG. 3 is another exemplary illustration of an exemplary catheterassembly of the surgical system of FIG. 1;

FIG. 4 is an illustration of an exemplary drive apparatus for anelongated member, e.g., a guidewire for a catheter;

FIG. 5 is a top view of the exemplary drive apparatus of FIG. 4;

FIG. 6 is a side view of the exemplary drive apparatus of FIG. 4;

FIG. 7 is a rear view of the exemplary drive apparatus of FIG. 4;

FIG. 8 is a perspective view of the exemplary drive apparatus of FIG. 4,with the dynamic gripper rotated to a maximum rotation in a clockwisedirection;

FIG. 9 is a perspective view of the exemplary drive apparatus of FIG. 4,with the dynamic gripper rotated to a maximum rotation in acounter-clockwise direction;

FIG. 10 is an illustration of another exemplary drive apparatus for anelongated member, e.g., a guidewire for a catheter;

FIG. 11 is another perspective view of the exemplary drive apparatus ofFIG. 10;

FIG. 12 is a front view of the exemplary drive apparatus of FIG. 10;

FIG. 13 is a rear view of the exemplary drive apparatus of FIG. 10;

FIG. 14 is another perspective view of the exemplary drive apparatus ofFIG. 10, with the grippers placed in an open position;

FIG. 15 is a front view of an exemplary instrument with a sterile drapeassembly;

FIG. 16 is a graph illustrating an exemplary proxy command for a driveapparatus;

FIG. 17 is a graph illustrating insert joint position for the exemplaryproxy command illustrated in FIG. 16;

FIG. 18 is a process flow diagram for an exemplary method of providing agenerally continuous motion using a discontinuous drive system, e.g.,the exemplary drive apparatus illustrated in FIGS. 4-9 and/or FIGS.10-14; and

FIG. 19 is a top view of an exemplary pivotable pad for a gripper.

DETAILED DESCRIPTION

Referring now to the drawings, illustrative embodiments are shown indetail. Although the drawings represent the embodiments, the drawingsare not necessarily to scale and certain features may be exaggerated tobetter illustrate and explain an innovative aspect of an embodiment.Further, the embodiments described herein are not intended to beexhaustive or otherwise limit or restrict the invention to the preciseform and configuration shown in the drawings and disclosed in thefollowing detailed description.

Exemplary System and Drive Apparatuses

Referring to FIG. 1, a robotically controlled surgical system 100 isillustrated in which an apparatus, a system, and/or method may beimplemented according to various exemplary illustrations. System 100 mayinclude a robotic catheter assembly 102 having a robotic or first orouter steerable complement, otherwise referred to as a sheath instrument104 (generally referred to as “sheath” or “sheath instrument”) and/or asecond or inner steerable component, otherwise referred to as a roboticcatheter or guide or catheter instrument 106 (generally referred to as“catheter” or “catheter instrument”). Catheter assembly 102 iscontrollable using a robotic instrument driver 108 (generally referredto as “instrument driver”). During use, a patient is positioned on anoperating table or surgical bed 110 (generally referred to as “operatingtable”) to which robotic instrument driver 108 may be coupled ormounted. In the illustrated example, system 100 includes an operatorworkstation 112, an electronics rack 114 and associated bedsideelectronics box (not shown), a setup joint mounting brace 116, andinstrument driver 108. A surgeon is seated at operator workstation 112and can monitor the surgical procedure, patient vitals, and control oneor more catheter devices. Operator workstation 112 may include acomputer monitor to display a three dimensional object, such as acatheter instrument or component thereof, e.g., a guidewire, cathetersheath. Moreover, catheter instrument 502 may be displayed within orrelative to a three dimensional space, such as a body cavity or organ,e.g., a chamber of a patient's heart. In one example, an operator uses acomputer mouse to move a control point around the display to control theposition of catheter instrument.

System components may be coupled together via a plurality of cables orother suitable connectors 118 to provide for data communication, or oneor more components may be equipped with wireless communicationcomponents to reduce or eliminate cables 118. Communication betweencomponents may also be implemented over a network or over the internet.In this manner, a surgeon or other operator may control a surgicalinstrument while being located away from or remotely from radiationsources, thereby decreasing radiation exposure. Because of the optionfor wireless or networked operation, the surgeon may even be locatedremotely from the patient in a different room or building.

Referring now to FIG. 2, an exemplary instrument assembly 200 is shown,including sheath instrument 104 and the associated guide or catheterinstrument 106 mounted to mounting plates 202, 204 on a top portion ofinstrument driver 108. During use, catheter instrument 106 is insertedwithin a central lumen of sheath instrument 104 such that instruments104, 106 are arranged in a coaxial manner. Although instruments 104, 106are arranged coaxially, movement of each instrument 104, 106 can becontrolled and manipulated independently. For this purpose, motorswithin instrument driver 108 are controlled such that carriages coupledto each of the instruments 104, 160 may allow the instruments 104, 106to be driven forwards and backwards along the driver 108, e.g., withmounting plates securing the instruments to the driver 108 on bearings.As a result, a catheter 300 coupled to guide catheter instrument 106 andsheath instrument 104 can be controllably manipulated while insertedinto the patient, as will be further illustrated. Additional instrumentdriver 108 motors (not shown in FIG. 2) may be activated to controlbending of the catheter as well as the orientation of the distal tipsthereof, including tools mounted at the distal tip. Sheath catheterinstrument 106 is configured to move forward and backward for effectingan axial motion of the catheter, e.g., to insert and withdraw thecatheter from a patient, respectively.

Referring now to FIG. 3, another exemplary instrument 109 is illustratedmounted on the exemplary instrument driver 108. The instrument 109includes a cover 111 and a drive apparatus, e.g., drive apparatus 400 ordrive apparatus 1000, as will be described further below. During use theinstrument 109 may be used to manipulate an elongate member included inthe catheter assembly 102, e.g., a catheter guidewire (not shown in FIG.3). Alternatively, the instrument 109 may be employed to manipulate acatheter sheath (not shown in FIG. 3). Although a single instrument 109is illustrated in FIG. 3, in another exemplary illustration twoinstruments 109 may be employed in which a first instrument 109 is usedto insert and roll a guidewire, which guidewire is inserted within acentral lumen of a second instrument 109 (not shown in FIG. 3) such thatthe two instruments 109 are arranged in a coaxial manner, substantiallyas described above regarding the instruments 104, 106. Additionally, theinstruments 109 may generally insert and rotate the associated elongatemember, i.e., the guidewire and catheter sheath, independently, asdescribed above regarding the instruments 104, 106. Accordingly, whilethe exemplary illustrations herein may generally focus on the insertionand rotation of a guidewire for a catheter, the instrument 109 may beused for insertion and rotation of any elongate member that isconvenient.

Turning now to FIGS. 4-9, exemplary drive apparatus 400 is illustratedin further detail. As noted above, and as will be described furtherbelow, the drive apparatus 400 may generally include a moveablecomponent 440. In the illustrated example, the moveable component 440 isa dynamic gripper 440. The drive apparatus may further comprise a firstcomponent 442. As illustrated in FIGS. 4-9, the first component 442 maybe a static gripper 442, and in some exemplary approaches the staticgripper 442 may be generally fixed with respect to the support surface401. Each of the grippers 440, 442 may comprise a clamp 445, 447 havinga pair of opposing pads 444 a, 444 b and 446 a, 446 b, respectively.Accordingly, the grippers 440, 442 may each selectively clamp anelongate member, e.g., a guidewire or catheter, between their respectiveopposing pads 444 a, 444 b and 446 a, 446 b.

The moveable component or dynamic gripper 440 may have a range of motionto which it is confined. For example, as will be described furtherbelow, the dynamic gripper 440 may be capable of axial movement in adirection A along a distance D. Additionally, the dynamic gripper 440may be capable of limited rotational movement about an axis parallel tothe direction of axial movement, e.g., to a range of plus or minus apredetermined angle with respect to a normal or center position.Nevertheless, the as described further below the dynamic gripper 440 maymove an elongated component across a predetermined movement, e.g., anaxial or rotational movement that may be provided by a user, that isgreater than the axial or rotational range of motion.

The pads 444 may each generally define a length L_(D) in the axialdirection associated with the elongate member, as best seen in FIG. 5.Similarly, the pads 446 may each generally define a length L_(S) in theaxial direction associated with the elongate member. As best seen inFIG. 6, the pads 444 may also each define a height H_(D) in a directionperpendicular to the axial direction, i.e., in a direction correspondingto a direction of top loading the elongate member, as will be describedfurther below. Moreover, the pads 446 may similarly each define a heightH_(S) in a direction perpendicular to the axial direction, i.e., in adirection corresponding to a direction of top loading the elongatemember, as will be described further below.

An elongated member, e.g., a guidewire, may be wrapped about a slipdetection wheel 406 that passively rotates in response to a length ofthe guidewire being moved by the dynamic grippers 440. The slipdetection wheel 406 may be mounted on a rotatable member 405. Moreover,as will be described further below the wheel 406 may include opticalmarks allowing for tracking of the wheel 406 rotation, thereby allowingmeasurement of movement and/or slippage of the elongate member.

As shown in FIG. 4, the grippers may each be mounted to a supportstructure 401, e.g., a top surface or support structure associated withthe driver 108. The grippers 440, 432 are each configured to selectivelygrip an elongate member such as a catheter guidewire or sheath, merelyas examples. Moreover, the dynamic gripper 440 is configured togenerally move axially and rotationally with respect to the supportstructure 401 to effect a corresponding axial and rotational movement ofthe elongated member. By contrast, the static gripper 442 is generallynot movable axially or rotationally with respect to the supportstructure 401. The static gripper 442 selectively closes and opens togrip and release the elongate member.

Generally, the static gripper 442 cooperates with the dynamic gripper440 to effect axial movement (i.e., for insertion) along a direction Aas illustrated in FIG. 4, and rotational movement R about the directionA of the elongate member. The grippers 440, 432 may generally work insequence such that at least one of the grippers 440, 432 is gripping theelongate member at any given time. More specifically, during anymovement of the guidewire, e.g., insertion, retraction, or rotationalmovement in either direction, the dynamic grippers 440 are closed, andstatic grippers 442 are open.

A range of axial motion associated with the dynamic grippers 440 may befinite, and in particular be limited to a predetermined axial distanceD, as seen in FIG. 6. Accordingly, upon reaching a limit to the range ofmotion, i.e., at an axially furthest position in one direction, thedynamic grippers 440 generally release the elongate member, move back inan opposite direction, and re-grip the elongated member for continuedaxial movement. While the dynamic grippers 440 are not gripping theelongated member, the static grippers 442 may hold the elongated memberin place to prevent movement or loss of position.

Axial and rotational motion of the elongated member may be governed byindependent drive systems associated with the drive apparatus 400. Forexample, the dynamic gripper 440 may have separate motors or mechanismscontrolling axial motion on the one hand and rotational motion on theother. Accordingly, insertion and rotation of the elongated member maybe accomplished completely independently of the other. Morespecifically, the elongated member may be inserted axially while it isbeing rotated, or the elongated member may be inserted without anyrotation. Moreover, the elongate member may be rotated without requiringany insertion motion at the same time.

Turning now to FIGS. 8 and 9, rotational motion of the dynamic grippers440 is described and shown in further detail. A rotation drive motor423, as best seen in FIG. 8, may rotate a gear 424 engaging a carriageor swing platform 425 configured to rotate about an axis of rotation,e.g., in a rotational motion R about the direction of insertion A. Thecarriage 425 may be located by a pair of rolling posts 422 supported bya base structure 434. The base structure 434 may in turn be secured tothe support structure 401. The carriage or swing platform 425 may becapable of rolling from a nominal or center position to any degree thatis convenient. In one exemplary illustration, the carriage or swingplatform 425 may be capable of rolling 30 degrees in either directionfrom a nominal or center position. More specifically, as illustrated inFIG. 8, swing platform 425 is rotated in a clock-wise direction thirtydegrees away from a nominal or center position, i.e., as shown in FIG.4. Moreover, as illustrated in FIG. 9, swing platform 425 is illustratedrotated in a counter-clock-wise direction away from the nominalposition.

Turning now to FIGS. 6 and 8, axial motion of the dynamic gripper 440 isillustrated in further detail. The dynamic gripper 440 may be axiallymoved by a shaft 426 which is linked to an axial drive motor 431 by wayof cam 430, as best seen in FIG. 6. The cam 430 may be connected to themotor 431 via gears 432, 433. The opposite end of the shaft 426 may beconnected to an axially movable platform 428 via a cam follower 427.Accordingly, the dynamic gripper 440 may be independently driven in anaxial direction, e.g., for insertion, by the axial drive motor 431, andmay be rotated independently by a rotation drive motor 423.

The static and dynamic grippers 442, 440 may each be configured to opento allow loading of an elongated member, e.g., a guidewire or catheter.Moreover, the grippers 440, 442 may generally allow “top loading” of thedrive apparatus 400 in a direction perpendicular to the axial motion ofthe gripper 440. More specifically, the grippers 440, 442 may eachgenerally open to allow the guidewire to be laid between the opengrippers, e.g., from above the apparatus 400, without needing to“thread” the elongated member into the grippers 440, 442 axially. Theability to load the elongated member without requiring the catheter tobe threaded through the drive apparatus 400 advantageously saves time,and also facilitates use of a sterile drape as will be described furtherbelow.

Turning now to FIGS. 5-7, the opening and closing of the static gripper442 and dynamic gripper 440 will now be explained in further detail. Thedynamic gripper 440 may be opened by a grip open motor 407. For example,as best seen in FIGS. 5 and 6, a grip open motor 407 may be providedwhich drives a cam 408, which in turn actuates shaft 9. The shaft 9 hasa cam follower 410 that provides axial motion to movable platform 411and cam follower 412, which is attached to the lever 413 (see FIG. 6).The lever 13, as seen in FIG. 5, provides lateral motion through arotation over shaft 414 to a dynamic gripper bracket 416 by way of camfollower 415. Cam 408 thus may generally provide only one way motion, toopen the dynamic grippers 440. On the other hand, the dynamic grippersmay be urged toward a closed position by a set of springs 417. Forexample, the springs 417 may act between the opposing pads included inthe dynamic grippers 440, thereby urging the grippers 440 into a closedposition absent a force applied by the grip open motor 407 to counteractthe closing force of the springs 417.

As noted above, the static gripper 442 may be selectively opened andclosed, independent of the opening and closing of the dynamic gripper440. Nevertheless, the same cam 408 employed to open the dynamicgrippers 440 may be used to selectively open the static grippers 442.For example, as best seen in FIG. 7, the cam 408 may include twoseparate profiles, with one configured to open the dynamic grippers 440,and another configured to open the static grippers 442. Morespecifically, the cam 408 as seen in FIG. 7 may be in proximity to a camfollower 418 that is connected to static gripper platform 419. Thestatic gripper platform 419 may urge the opposing pads of the staticgrippers 442 apart. One or more compliant elements, e.g., spring 420,may generally urge the static gripper platform 419 toward a closedposition where the static grippers 442 are clasped together, e.g., abouta guidewire or catheter.

The platform 425 on which the dynamic grippers 440 are mounted maygenerally move in relation to the support surface 401, as noted above.The platform 425 thus may also be moving in relation to the cam follower410, shaft 409, and cam 408 used to effect opening and closing movementof the dynamic grippers 440. Accordingly, the movement of the shaft 409is in relation to the moving platform 425, and thus the opening movementof the cam 408 may need to account for this additional relative movementin order to open the dynamic grippers 440.

As briefly described above, the grippers 440, 442 generally allow a toploading of the elongated member, e.g., a guidewire, thereby increasingthe speed with which the guidewire may be loaded into the driveapparatus 400. Additionally, the positioning of the grippers 440, 442and the opposing pads 444, 446 may also facilitate the use of a steriledrape that generally maximizes the potential for reusing components ofthe drive apparatus 400. In other words, the sterile drape may allow forkeeping nearly the entire drive apparatus 400 out of the sterileenvironment, defining in part a disposable portion of the system 100that is within the sterile environment.

Turning now to FIGS. 10-14, another exemplary drive apparatus 1000 isillustrated in further detail. The drive apparatus 1000 may generallyinclude a moveable component such as a dynamic gripper 1050. The driveapparatus may further comprise a fixed component. In the exampleillustrated in FIGS. 10-14, the fixed component includes at least onestatic gripper. As illustrated in FIGS. 10-14 the fixed componentincludes two static grippers 1052 a, 1052 b. More specifically, thefixed component includes a first static gripper 1052 a, and a secondstatic gripper 1052 b. The dynamic gripper 1050 may comprise a pair ofopposing pads 1003, 1004. Similarly, a first one of the static grippers1052 a may comprise a pair of opposing pads 1005 a, 1006 a, and theother static gripper 1052 b may also comprise a pair of opposing pads1005 b, 1006 b. Accordingly, the grippers 1050, 1052 a, and 1052 b mayeach selectively clamp an elongate member, e.g., a guidewire orcatheter, between their respective opposing pads 1003/1004, 1005 a/1006a, and 1005 b/1006 b. The pads 1003/1004, 1005 a/1006 a, and 1005 b/1006b may each be relatively soft with respect to the particular elongatemember being employed, in order to more securely grip the elongatemember and minimize potential damage to the elongate member, e.g., byspreading grip load across an increased surface area of the elongatemember.

As best seen in FIGS. 12 and 13, the pads 1003, 1004 of the dynamicgripper 1050 each define generally arcuate profiles for engaging theelongate member (not shown in FIGS. 12 and 13). More specifically, thepads 1003, 1004 each have curved pad surfaces 1098, 1099, respectively.Accordingly, the pads 1003, 1004 may engage an elongate member along alongitudinal line extending parallel to the elongate member, i.e.,axially with respect to the dynamic gripper 1050. In other exemplaryapproaches, the surfaces of the pads 1003, 1004 may be generally flat.The pads 1005 a/1006 a and 1005 b/1006 b of the static grippers 1052 a,1052 b, respectively, may similarly define either curved or flatengagement surfaces for engaging an elongate member.

Turning now to FIG. 19, in another exemplary approach one of the pads1003′ of a dynamic gripper 1050′ may be pivotable about a substantiallyvertical axis A-A with respect to an opposing pad 1004′. While the pads1003/1004, 1005 a/1006 a, and 1005 b/1006 b described in regard to FIGS.10-14 are illustrated as being generally fixed rotationally with respectto one another, a pivotable pad 1003′ may be employed in place of any ofthe rotationally fixed pads. The pivotable pad 1003′ may generallyimprove grip of an elongate member by minimizing any loss of grip due tomisalignment of the pad 1003′ or 1004′. More specifically, to any extentthe pad 1004′ is possibly misaligned, the pad 1003′ will generallyautomatically rotate about the vertical axis A-A as the associatedgripper, e.g., dynamic gripper 1050, closes upon the elongate member.The pivoting pad 1003′ may thereby ensure a substantially parallelalignment of the two pads 1003′, 1004′ as the gripper 1050′ closes uponthe elongate member. Moreover, the pivotable pad concept may be appliednot only to a dynamic gripper 1050′, but also to a static gripper, e.g.,static grippers 1052 a, 1052 b.

Similar to the drive apparatus 400, the moveable component or dynamicgripper 1050 of the drive apparatus 1000 may have a predetermined rangeof motion which it is confined to. For example, as will be describedfurther below, the dynamic gripper 1050 may be capable of axial movementin a direction A along a predetermined distance D₂ (see FIG. 10).Additionally, the dynamic gripper 1050 may be capable of imparting alimited rotational movement to the elongate member about an axisparallel to the direction of axial movement, e.g., to a range of plus orminus a predetermined angle with respect to a normal position. Morespecifically, as will be described further below the pads 1003, 1004 ofthe dynamic gripper 1050 may generally translate vertically with respectto one another across a limited range of translational motion, e.g., asdefined by a gear and rack system. Nevertheless, the dynamic gripper1050 may move an elongated component across a movement, e.g., an axialor rotational movement, for example as commanded by a user or surgeon,that is greater than the predetermined axial or rotational motioncapable of the dynamic gripper 1050 in a single vertical stroke of thedynamic grippers 1050.

The pads 1003, 1004 of the dynamic gripper 1050 may generally define alength L_(D) in the axial direction associated with the elongate member,as best seen in FIG. 14. Similarly, the pads 1005 a, 1006 a and 1005 b,1006 b of the first and second static grippers 1052 a, 1052 b,respectively, may generally define respective lengths L_(S1), L_(S2) inthe axial direction associated with the elongate member. Similar to theheights HD and Hs described above regarding drive apparatus 400, thepads 1003/1004, 1005 a/1006 a, and 1005 b/1006 b may each generallydefine an axial height, i.e., in a direction perpendicular to thedirection of axial insertion A and corresponding to a direction fromwhich an elongated member may be placed in between the pads. Forexample, as best seen in FIG. 12, the pads 1003, 1004 of the dynamicgrippers 1050 may define respective axial heights H₂ and H₁, which maybe equal. The pads 1003/1004, 1005 a/1006 a, and 1005 b/1006 b may eachgenerally be open to a space above the pads when opened, e.g., as shownin regard to the dynamic pads 1003, 1004 in FIG. 12, allowing anelongated member extending across the pads axially to be laid in betweenthe pads 1003/1004, 1005 a/1006 a, and 1005 b/1006 b.

An elongated member, e.g., a guidewire, may be wrapped about slipdetection wheel 1002 that passively rotates in response to a length ofthe guidewire being moved by the dynamic grippers 1050. The slipdetection wheel 1002 may be mounted on a support 1001. Moreover, as willbe described further below the wheel 1002 may include optical marksallowing for tracking of the wheel 1002 rotation, thereby allowingmeasurement of movement of the elongate member. It should be noted thatfor stiffer elongate members, it may not be necessary to wrap theelongate member about the slip detection wheel. Instead, the wheel maybe configured to just contact the elongate member and rotation isimparted to the passive wheel via friction between the wheel and thesurface of the elongate member.

As shown in FIG. 10, the static grippers 1052 a, 1052 b and dynamicgripper 1050 may each be mounted to a support structure 999, e.g., a topsurface or support structure associated with the driver 108. Thegrippers 1050, 1052 are may each be configured to selectively grip anelongate member such as a catheter guidewire or sheath, merely asexamples. Moreover, the dynamic gripper 1050 is configured to generallymove axially with respect to the support structure 999 to effect acorresponding axial movement of the elongated member. The pads 1003,1004 of the dynamic gripper 1050 are also configured to translate in avertical direction across a fixed range of motion to impart rotationalmotion to the elongate member with respect to the support structure 999.By contrast, the static grippers 1052 a and 1052 b are generally notmovable axially or rotationally with respect to the support structure401. The static grippers 1052 a and 1052 b selectively close and open togrip and release the elongate member.

Generally, similar to the drive apparatus 400 described above, thestatic grippers 1052 a and 1052 b of the drive apparatus 1000 eachcooperate with the dynamic gripper 1050 to effect axial movement (i.e.,for insertion or retraction) along a direction A as illustrated in FIG.10, and rotational movement R about the direction A of the elongatemember. The static grippers 1052 a, 1052 b may generally work insequence with the dynamic grippers 1050 such that at least one of thegrippers 1050, 1052 a, and 1052 b is gripping the elongate member at anygiven time. More specifically, during any movement of the guidewire,e.g., insertion, retraction, or rotational movement in either direction,the dynamic grippers 1050 are closed, and the static grippers 1052 a and1052 b are open. Moreover, the static grippers 1052 a, 1052 b maygenerally work in concert, such that the static grippers 1052 a, 1052 bare either both open or both closed together.

A range of axial motion associated with the dynamic grippers 1050 may befinite, and in particular be limited to a predetermined axial distanceD₂, as seen in FIG. 10. In the illustrated example having two staticgrippers 1052 a, 1052 b, a range of motion of the dynamic gripper 1050may be limited by the static gripper 1052 a on one end and the otherstatic gripper 1052 b on the other end. However, as noted above, inother exemplary approaches only one static gripper 1052 may be present,and thus the axial motion of the dynamic gripper 1050 may be limited byother factors. Nevertheless, the dynamic gripper 1050 may have somepredetermined range of axial motion. Accordingly, upon reaching a limitto the range of motion, i.e., at an axially furthest position in onedirection, the dynamic grippers 1050 generally release the elongatemember, move back in an opposite direction, and re-grip the elongatedmember for continued axial movement. While the dynamic grippers 1050 arenot gripping the elongated member, the static grippers 1052 a and/or1052 b may hold the elongated member in place to prevent movement of theelongated member or loss of position.

Axial and rotational motion of the elongated member may be governed byindependent drive systems associated with the drive apparatus 1000, aswith drive apparatus 400. For example, the dynamic gripper 1050 may haveseparate motors or mechanisms controlling axial motion on the one handand rotational motion on the other. Accordingly, insertion and rotationof the elongated member may be accomplished completely independently ofthe other. More specifically, the elongated member may be insertedaxially while it is being rotated, or the elongated member may beinserted without any rotation. Moreover, the elongate member may berotated without requiring any insertion motion at the same time.

Referring now to FIGS. 10, 13, and 14, opening and closing of thegrippers is described and shown in further detail. The drive apparatus1000 may be generally closed initially. In order to open the grippers,lever 1011 may be manually moved to a vertical position, e.g., asillustrated in FIG. 14. The movement of the lever 1011 may rotate ashaft 1012 that is configured to move a static pad bracket 1013 which inturn opens the static pads 1005 a and 1005 b with respect to theircorresponding static pads 1006 a and 1006 b, respectively. A dynamic padbracket 1014 may open the dynamic pads 1003, 1004 of the dynamic gripper1050 in a similar manner. In one exemplary illustration, cams may bepositioned on the shaft 1012 for urging the brackets 1013, 1014 in adirection opening the pads of each of the static grippers 1052 a, 1052 band the dynamic grippers 1050, respectively. Moreover, the pads of thestatic grippers 1052 a, 1052 b and the dynamic grippers 1050 may beopened in sequence, i.e., separately from one another. For example, asbest seen in FIGS. 10, 13, and 14, cams 1015 and 1016 may be connectedby a coupling 1017 that is driven by motor 1010. The cams 1015, 1016 mayact upon the static pad bracket 1013 and dynamic pad bracket 1014,respectively, thereby opening each. The static pad bracket 1013 may beurged into a closing position by a spring 1030, while the dynamic padbracket 1014 may be urged into a closing position by a spring 1031.Accordingly, the static pad bracket 1013 and dynamic pad bracket 1014generally may remain closed in the absence of a force applied to thebrackets 1013, 1014 tending to open either of the brackets 1013, 1014.

Turning now to FIGS. 10, 11, and 12, axial motion of the drive apparatus1000, e.g., for insertion or retraction of an elongate member, isdescribed in further detail. Axial movement of the dynamic gripper 1050,i.e., to effect an insertion or refraction motion of the dynamic gripper1050, may be driven by a cam 1007 that is turned by motor 1008, as bestseen in FIG. 11. More specifically, cam follower 1018 may follow thecam, e.g., within a groove 1060 defined by the cam 1007, therebyimparting axial motion to dynamic gripper 1050, including both of theopposing pads 1003, 1004.

Turning now to FIGS. 10 and 12 a mechanism for imparting a rotationalmotion to an elongate member using the drive apparatus 1000 is describedin further detail. As best seen in FIG. 12, which is a cross section ofthe apparatus 1000, a gear shaft 1020 may be connected through acoupling to a dedicated motor 1009 (see FIG. 10). The gear shaft 1020may provide relative vertical motion to a first gear rack 1019 that isopposed by a second gear rack 1021. The relative vertical motion istransferred to the dynamic gripper 1050. More specifically, a first oneof the pads 1003 of the dynamic gripper 1050 translates upward anddownward with the first gear rack 1019, while the other pad 1004translates upward and downward with the second gear rack 1021.Accordingly, the relative vertical movement between the pads 1003, 1004imparts a rolling motion to an elongate member held between the pads1003, 1004.

Pads 1003 and 1004 may be designed to optimize the gripping and rollingperformance of the elongate member. For example, in one exemplaryillustration, a high durometer material that does not engulf theelongate member is used, which may generally prevent pads 1003 and 1004from contacting each other. This ensures that the spring force closingthe grippers is substantially entirely applied to the elongate memberand is not transferred from one gripper to the other, ensuring reliablegrip on the elongate member. In another exemplary illustration, thecontact surface of the pads 1003 and 1004 is beveled in a convex shapesuch that there is less chance that the pads will contact each other dueto any misalignment or non parallelism in the gripper mechanism.

Initially, the pads 1003, 1004 of the dynamic grippers 1050 and the pads1005 a, 1006 a, 1005 b, 1006 b of the static grippers 1052 a, 1052 b maybe manually opened with the lever 1011, as best seen in FIG. 10. Anelongate member, e.g., a guidewire, may be top loaded into the apparatus1000. More specifically, a guidewire may be loaded around wheel 1002 andlaid in between the pads 1005 a and 1006 a of the first static gripper1052 a, the pads 1003 and 1004 of the dynamic gripper 1050, and the pads1005 band 1006 b of the second static gripper 1052 b. More specifically,the elongate member may generally be laid between the pads 1003/1004,1005 a/1006 a, and 1005 b/1006 b from above, allowing the elongatemember to be extended and laid in between the pads instead of requiringthat the elongate member be threaded axially through the pads. Duringaxial motion, e.g., insertion or retraction, an elongate member such asa guide wire or catheter will be pulled off of or pushed onto wheel1002, which may passively rotate according to the insertion motiondriven by the dynamic gripper 1050 with respect to a wheel support 1001of the drive apparatus 1000. As noted above, rotation of the wheel 1002may be monitored, e.g., by an optical sensor, to allow for measurementof any axial movement of the elongate member. During axial movement ofthe elongate member, e.g., insertion or retraction, and also duringrotational movement, the dynamic pads 1003 and 1004 are generallyclosed, thereby trapping the elongate member therebetween as a result ofa grip imparted to the elongate member or guidewire. Additionally,during axial or rotational motion of the elongate member, the pads 1005a, 1006 a of the first static gripper 1052 a and the pads 1005 b, 1006 bof the second static gripper 1052 b remain open, thereby generallyfreely allowing relative movement of the elongate member with respect tothe static grippers 1052 a, 1052 b. Upon reaching a limit of rotationalor axial motion, the pads 1005 a, 1006 a of the first static gripper1052 a and the pads 1005 b, 1006 b of the second static gripper 1052 bmay be closed. The pads 1003 and 1004 of the dynamic gripper 1050 maythen be opened, and moved within its range of motion (i.e., alongdistance D) to allow regripping of the elongated member, while thestatic grippers 1052 a, 1052 b maintain the axial and rotationalposition of the elongated member. The cycle may then be repeated toallow further axial and/or rotational movement of the elongated member.

Turning now to FIG. 15, an exemplary sterile drape assembly isillustrated. An exemplary drape assembly may include a sterile drape 500generally positioned over the instrument 109. The sterile environmentmay thereby be confined to the area above the drape 500, allowing useand reuse of the instrument 109 and essentially all components thereofthat are positioned beneath the drape. The drape 500 may be positionedover a set of grippers 504 a, 504 b using associated caps 501 a, 501 b.For purposes of the illustration shown in FIG. 15, the grippers 504 a,504 b may correspond to any of the static grippers 1052 a, 1052 b ordynamic grippers 1050 of the apparatus 1000, or the static gripper 442or dynamic gripper 440 of the apparatus 400. For example, the caps 501may be molded into the drape 500, and may be fitted to the grippers 504,thereby securing the drape 500 in place over the grippers 504. Moreover,the caps 501 may generally allow for gripping of an elongated member,e.g., a guidewire or catheter, using the caps 500, thereby allowing theelongated member to be in the sterile environment. The drape 500 andcaps 501 may be included in a disposable portion of the system 100,i.e., which must be disposed of after a procedure, while substantiallyall components of the system 100, and in particular the drive apparatus400 or drive apparatus 1000, is kept out of the sterile environment andtherefore may be reused.

It should be understood that the designs presented here are merelyexemplary. For example, while apparatus 400 and apparatus 1000 are bothdescribed as having one set of fixed grippers and one set of dynamicgrippers, alternative approaches may have two pairs of dynamic grippersinstead of one static pair and one dynamic pair. The second pair ofdynamic grippers may perform similar duties as the static grippersdescribed herein with respect to the first set of dynamic grippers(i.e., hold the elongate member while the first dynamic gripper isreturning). Moreover, the second dynamic gripper may also apply axialand rotation movement just like the first dynamic gripper.

It should also be understood that the stroke length and gripper lengthshown for apparatuses 400 and 1000 are also merely exemplary. Forexample, the distance between the grippers which is approximately equalto the stroke length is shown to be approximately the same length aseach of the grippers. This may not be true in all cases. For example,for stiffer elongate members that have greater buckling strength, theremay be a significantly longer length between the grippers, oreffectively a significantly longer stroke. In addition, if the elongatemember that is being manipulated has a high friction surface, thenshorter grippers may be appropriate. Also, the length of the static anddynamic grippers are shown to be equal. It is likely that the staticgripper length may be shorter than the dynamic gripper since the staticgripper just needs to hold the device.

The rotational mechanism of apparatus 400 is shown to have approximately60° of rotation in both directions. Again, this is merely an exemplaryillustration. The 60 degrees of rotation may generally permit a doctorto intervene manually and remove the robotic system if the roboticsystem is stopped at any point during a procedure, and the guidewirewill always be presentable towards the top of the mechanism for removal.If for example, there was 180° of rotational movement on this mechanism,there may be times when the grippers are inverted making it difficult toremove the guidewire. In addition, large rotational strokes make it moredifficult to manage the sterile barrier because eit may lead to morewinding up of the drape. Nevertheless, any angle of rotation may beemployed that is convenient.

It should also be noted that even though most of the descriptions usedhere describe the elongate member as a guidewire, it may also be acatheter, a sheath, a microcatheter, a therapeutic device such as astent or balloon or artherectomy device for example.

Control of Discontinuous/Finite Drive Apparatus to ProvideContinuous/Infinite Movement

As noted above, the dynamic gripper 440 of the apparatus 400 and thedynamic gripper 1050 of the apparatus 1000 generally may have a finiterange of motion in the axial direction, i.e., a range of motion acrossan axial distance D as best seen in FIGS. 6 and 10, respectively.Additionally, the dynamic grippers 440 and 1050 have a finite range ofrotational motion, i.e., a maximum angle from a nominal position asdictated by the configuration of the swing platform 425 seen in FIGS. 8and 9 and the geared rack system 1019, 1021 illustrated in FIG. 12.Accordingly, to provide an axial insertion across a distance greaterthan distance D, the dynamic grippers 440 and 1050 generally mustrelease the guidewire as it reaches a position toward or at an end ofits range of motion, move axially rearward and then re-grip theguidewire, and continue the axial insertion. Similarly, to provide arotation to an angle greater than the maximum angle capability of theswing platform 425 or the geared rack system 1019, 1021, the dynamicgrippers 440, 1050 generally must release the guidewire as the swingplatform 425 and geared rack system 1019, 1021 reaches a maximum angulartravel, allowing the respective systems to move in the oppositerotational direction and re-grip the guidewire to continue rotating theguidewire. The process of gripping and re-gripping an elongate membermay occur many times during a given axial or rotational movementcommand.

Accordingly, it may be necessary to track a user command associated withthe drive apparatus 400 and 1000, and selectively adjust the movement ofthe drive apparatus 400 and 1000 to generally keep a resulting movementof the drive apparatus 400 and 1000 and associated elongated member asclose as possible to the commanded movement. In this sense, thechallenge is to track a continuous command, i.e., to move or rotate acertain amount, with a discontinuous mechanism having a maximum axialstroke length D or maximum angular rotation that is a smaller magnitudethan the commanded movement.

In one exemplary illustration, an intermediate or proxy command isemployed that is internal to a control system, e.g., included inoperator workstation 112 or electronics rack 114 of the system 100, orincorporated as part of the drive apparatus 400 or 1000. The controllermay generally be aware of the above movement limitations of themechanism, and may accordingly determine an appropriate movement inresponse to a given command. Referring now to FIG. 16, an exemplaryproxy command is illustrated for an exemplary drive apparatus 400. Inthis example, the thicker line represents a commanded position providedby the user of the system, while the thinner line illustrates anexemplary proxycommand. The proxy command is generally developedinternally by the controller based on the user command and the physicalrealities of the mechanism.

Generally, when the drive apparatus 400, 1000 is away from the end ofits range of motion (either axially or rotationally), the proxy commandmay track the user command tightly. Once the drive apparatus 400, 1000gets to the end of its range of motion, however, the proxy command mayfreeze while the mechanism clutches and resets to allow continueddriving. When the mechanism is finished with its clutching motion, theproxy command then catches up with the drive command such that thedeviation between the commanded position of the wire and the actual wireposition is as small as possible for as short a period of time aspossible.

Accordingly, the motion of the proxy command may be controlled by aprocess using two general states for the proxy command: a “freeze” stateand a “tracking” state. More specifically, the proxy command may enterthe “freeze” state whenever the mechanism under control, i.e., the driveapparatus 400, 1000 indicates that it cannot currently drive. Forexample, when a user is commanding an insertion motion of 40 millimetersand there is only 20 millimeters remaining the axial range of motion ofthe drive apparatus 400, 1000, the proxy command may enter the freezestate. Additionally, the freeze state associated with the proxy commandmay be employed for other purposes, such as when the drive mechanism isdeactivated or taken off line, e.g., for diagnostics.

The proxy command spends most of the time in the tracking state. In thetracking state, the proxy command follows the user command with dynamicsthat generally dictate how the proxy command catches up with the usercommand when it leaves the freeze state. The dynamics can generally betuned to achieve whatever behavior is desired for the particular driveapparatus 400, 1000. Depending on the application, the dynamics mayprovide as smooth and slow a transition as possible, e.g., forprocedures where insertion of an elongated member is necessarily veryslow; alternatively, the dynamics may provide for as fast and abrupt atransition as possible, or any blend of the two extremes.

In one exemplary illustration, the proxy command is a filtered versionof the user command. When the proxy command leaves the freeze state, thefilter is reset such that the filter naturally follows a smoothtrajectory connecting the proxy command with the user command. Merely asexamples, a first order or second order low-pass filter may be employed.In another example, a non-linear filter that includes features such aslimiting the maximum speed of the proxy may be employed. A second orderfilter may advantageously mimic, in terms of the proxy command dynamics,a mass-spring-damper system, i.e., where the proxy can be thought of asa mass which is connected to the user command by a spring and a damper.

A proxy command may be mapped to the actual joint commands of themechanism in any manner that is convenient. In one exemplaryillustration of the drive apparatus 400, 1000, the joint command may bereset at the end of every clutching cycle, i.e., when the dynamicgrippers 440, 1050 release, move to accommodate additional insertion orrotational motion, and re-grip the elongated member, to be at either thefront or the end of the range of motion. The joint command may beincremented by the same amount as the proxy command was incrementedevery cycle. For example as illustrated in FIG. 17, an actual jointposition command that was sent to the drive apparatus 400, 1000 for thesame data set as shown in FIG. 16.

In another exemplary illustration, the drive apparatus 400, 1000 may beconfigured to track a user command for axial motion or rotation of theelongate member by increasing actual velocity of components of the driveapparatus 400, 1000 relative to a velocity expected werereleasing/re-gripping not necessary. For example, when there is anexpectation that the dynamic grippers 440, 1050 will need to re-grip theelongate member, e.g., due to a commanded motion being beyond the rangeof motion of the dynamic grippers 440, 1050, the grippers 440, 1050 mayincrease a velocity of the movement, even in some cases “getting ahead”of the commanded motion. Accordingly, the movement of the elongatemember may be preventing from falling behind or falling undesirably farbehind a commanded motion. In other words, a drive apparatus 400, 1000or associated control system may generally compensate for the need torelease and re-grip the elongate member by increasing a velocity of acomponent associated with a commanded motion. In another exemplaryillustration, an actual position of an elongated member may be keptwithin a predetermined range of a commanded movement, i.e., slightlyahead or behind a commanded position, to account for the periodicreleasing and re-gripping of the elongate member. Moreover, any velocityor positional adjustments may be performed without intervention by thesurgeon, such that the process of releasing and re-gripping the elongatemember is generally undetected. In some exemplary approaches, control ofany buffer between the commanded position/velocity and actualposition/velocity may be quick enough that any positional difference orvelocity different resulting from the need to start and stop movement ofthe elongated member to allow release and re-gripping may generally beimperceptible by the user, e.g., the surgeon.

Turning now to FIG. 18, an exemplary process 1300 for a proxy command isillustrated. The process 1300 is generally begins at block 1302, wherethe process may query whether a commanded movement of the driveapparatus is within an associated limit to the range of motion.

If a commanded movement is within the range of motion, process 1300proceeds to block 1304, where the tracking state is set. In other words,if a movement of 40 millimeters is requested by an operator, and 60millimeters of travel remain in the axial insertion range of the driveapparatus, the proxy command may be equal to the user command.

On the other hand, if the commanded movement is outside the range ofmotion, then the process 1300 proceeds to block 1306, where the proxycommand may enter the freeze state. As noted above the freeze state mayallow the drive apparatus 400, 1000 to release and re-grip the elongatedmember in order to reduce or eliminate the shortfall between thecommanded motion and the capability of the drive apparatus 400, 1000.For example, if a rotational movement of 45 degrees is commanded by theuser and the maximum rotation available from the current position of thedynamic gripper 440, 1050 is only 35 degrees, then the proxy command mayenter the freeze state to allow the dynamic grippers 440, 1050 to bereleased and rotated to allow greater range of rotational movement.

Proceeding to block 1308, the dynamic grippers 440, 1050 are opened torelease the elongate member from their grip, and the dynamic grippers440, 1050 are then moved to allow greater range of motion and re-gripthe elongate member to reduce or eliminate the shortfall between theproxy command and the user command. Process 1300 may then proceed toblock 1310.

At block 1310, the commanded position may be compared with the proxycommand position, i.e., to determine any shortfall between the newposition of the dynamic grippers 440, 1050 and the desired or commandedposition.

Proceeding to block 1312, the proxy command may be adjusted with thedifference determined at block 1310. As noted above, in some examplesthe proxy command may be a filtered version of the comparison betweenthe proxy command and the user command, in order to “smooth” theresponse of the system to differences between the commanded position andthe current position of the dynamic grippers. Moreover, the transitionmay be tuned according to the desired response. A relatively slowertransition may be employed in situations where any relatively sudden orrelative large movement is especially problematic, while a fastertransition may be employed where speed or responsiveness is moreessential. Process 1300 may then terminate.

Operator workstation 112, electronics rack 114, drive apparatus 400,and/or drive apparatus 1000 may include a computer or a computerreadable storage medium implementing the operation of drive andimplementing the various methods and processes described herein, e.g.,process 1300. In general, computing systems and/or devices, such as theprocessor and the user input device, may employ any of a number ofcomputer operating systems, including, but by no means limited to,versions and/or varieties of the Microsoft Windows® operating system,the Unix operating system (e.g., the Solaris® operating systemdistributed by Oracle Corporation of Redwood Shores, Calif.), the AIXUNIX operating system distributed by International Business Machines ofArmonk, N.Y., the Linux operating system, the Mac OS X and iOS operatingsystems distributed by Apple Inc. of Cupertino, Calif., and the Androidoperating system developed by the Open Handset Alliance.

Computing devices generally include computer-executable instructions,where the instructions may be executable by one or more computingdevices such as those listed above. Computer-executable instructions maybe compiled or interpreted from computer programs created using avariety of programming languages and/or technologies, including, withoutlimitation, and either alone or in combination, Java™, C, C++, VisualBasic, Java Script, Perl, etc. In general, a processor (e.g., amicroprocessor) receives instructions, e.g., from a memory, acomputer-readable medium, etc., and executes these instructions, therebyperforming one or more processes, including one or more of the processesdescribed herein. Such instructions and other data may be stored andtransmitted using a variety of computer-readable media.

A computer-readable medium (also referred to as a processor-readablemedium) includes any non-transitory (e.g., tangible) medium thatparticipates in providing data (e.g., instructions) that may be read bya computer (e.g., by a processor of a computer). Such a medium may takemany forms, including, but not limited to, non-volatile media andvolatile media. Non-volatile media may include, for example, optical ormagnetic disks and other persistent memory. Volatile media may include,for example, dynamic random access memory (DRAM), which typicallyconstitutes a main memory. Such instructions may be transmitted by oneor more transmission media, including coaxial cables, copper wire andfiber optics, including the wires that comprise a system bus coupled toa processor of a computer. Common forms of computer-readable mediainclude, for example, a floppy disk, a flexible disk, hard disk,magnetic tape, any other magnetic medium, a CD-ROM, DVD, any otheroptical medium, punch cards, paper tape, any other physical medium withpatterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, any othermemory chip or cartridge, or any other medium from which a computer canread.

Databases, data repositories or other data stores described herein mayinclude various kinds of mechanisms for storing, accessing, andretrieving various kinds of data, including a hierarchical database, aset of files in a file system, an application database in a proprietaryformat, a relational database management system (RDBMS), etc. Each suchdata store is generally included within a computing device employing acomputer operating system such as one of those mentioned above, and areaccessed via a network in any one or more of a variety of manners. Afile system may be accessible from a computer operating system, and mayinclude files stored in various formats. An RDBMS generally employs theStructured Query Language (SQL) in addition to a language for creating,storing, editing, and executing stored procedures, such as the PL/SQLlanguage mentioned above.

In some examples, system elements may be implemented ascomputer-readable instructions (e.g., software) on one or more computingdevices (e.g., servers, personal computers, etc.), stored on computerreadable media associated therewith (e.g., disks, memories, etc.). Acomputer program product may comprise such instructions stored oncomputer readable media for carrying out the functions described herein.

Slip Detection and Correction

As noted above, an elongated member being used in connection with thedrive apparatus 400 may be fed from a feed wheel 406. Similarly, anelongated member associated with drive apparatus 1000 may be fed from awheel 1002. The feed wheels 406, 1002 may be configured to generallydetermine whether, when, and/or to what degree the elongated memberslips, e.g., axially, during axial motion imparted by the dynamicgrippers 440, 1050. For example, while the pads 444 a, b of the dynamicgripper 440 and the pads 1003, 1004 of the dynamic gripper 1050 mayinclude relatively high friction surfaces to prevent slippage of theelongated member, at times slippage may nonetheless occur, resulting ininaccuracies in the measured and commanded movements of the driveapparatuses 400 and 1000, respectively. Accordingly, the feed wheels406, 1002 may be used as a comparison with the movement of the dynamicgrippers 440, 1050 to determine when slippage occurs, and to whatdegree. For example, the feed wheel 406, 1050 may include an opticalreader that measures actual rotation of the feed wheels 406, 1002ultimately determining a length of the elongated member that is actuallydeployed from the feed wheel 406 at any given time. The actual movementof the elongated member may be compared with the commanded axialmovement to determine whether any slippage has occurred, and maysubsequently adjust movement of the dynamic grippers 440 accordingly.

In one example, a sensor (not shown in FIGS. 4-14) is within view of thefeed wheels 406, 1002 and is outside of the sterile environment suchthat it need not be replaced after a procedure. More specifically, ifthe feed wheels 406, 1002 are within the sterile environment, a sensormay be placed on an opposite side of an optically clear section of asterile drape (not shown in FIGS. 4-14), thereby allowing the sensor toremain outside the sterile environment and reduce the frequency withwhich the sensor itself must be sterilized or replaced. In anotherexemplary illustration, both the sensor and the feed wheels 406, 1002are outside the sterile environment. Merely as examples, a texturedsurface (not shown) may be positioned on the feed wheels 406, 1002 thatis detectable via the sensor. As such, a linear position of an elongatemember may be detected using the sensor in any manner that isconvenient.

In another exemplary illustration, a sensor outside the sterile field isconfigured to detect motion of the elongate member and a feed wheel isnot necessary. This may be suitable for elongate devices such ascatheters that have a braided surface or guidewires that have stripes onthe outer extrusion. This detail on the surface of the elongate membermay be detected by the sensor to detect motion.

In another exemplary illustration of a slip detection system, one ormore idle rollers may be in communication with the elongated member,such that the rollers provide a measure of the length of the elongatedmember supplied. The measured length may then be compared with thecommanded length in order to determine whether any slippage hasoccurred, allowing the system to adjust subsequent commands from thesystem.

CONCLUSION

The exemplary illustrations are not limited to the previously describedexamples. Rather, a plurality of variants and modifications arepossible, which also make use of the ideas of the exemplaryillustrations and therefore fall within the protective scope.Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive.

With regard to the processes, systems, methods, heuristics, etc.described herein, it should be understood that, although the steps ofsuch processes, etc. have been described as occurring according to acertain ordered sequence, such processes could be practiced with thedescribed steps performed in an order other than the order describedherein. It further should be understood that certain steps could beperformed simultaneously, that other steps could be added, or thatcertain steps described herein could be omitted. In other words, thedescriptions of processes herein are provided for the purpose ofillustrating certain embodiments, and should in no way be construed soas to limit the claimed invention.

Accordingly, it is to be understood that the above description isintended to be illustrative and not restrictive. Many embodiments andapplications other than the examples provided would be upon reading theabove description. The scope of the invention should be determined, notwith reference to the above description, but should instead bedetermined with reference to the appended claims, along with the fullscope of equivalents to which such claims are entitled. It isanticipated and intended that future developments will occur in the artsdiscussed herein, and that the disclosed systems and methods will beincorporated into such future embodiments. In sum, it should beunderstood that the invention is capable of modification and variationand is limited only by the following claims.

All terms used in the claims are intended to be given their broadestreasonable constructions and their ordinary meanings as understood bythose skilled in the art unless an explicit indication to the contraryin made herein. In particular, use of the singular articles such as “a,”“the,” “the,” etc. should be read to recite one or more of the indicatedelements unless a claim recites an explicit limitation to the contrary.

What is claimed is:
 1. A drive apparatus, comprising: a static grippingdevice fixed rotationally and axially with respect to a support surface,the static gripping device configured to selectively grip an elongatemember; and a dynamic gripping device mounted to the support surface andconfigured to selectively grip the elongate member and move axially androtationally with respect to the support surface to effect axialmovement and rotational movement, respectively, of the elongate memberwith respect to the support surface, wherein the dynamic gripping deviceis confined to a range of motion comprising a limited axial distance anda limited rotational angle; wherein the static gripping device isconfigured to cooperate with the dynamic gripping device such that theselective gripping of the static gripping device, the selective grippingof the dynamic gripping device, and the axial and rotational movement ofthe dynamic gripping device are coordinated to move the elongate memberan axial distance greater than the limited axial distance and rotate theelongate member an angle greater than the limited rotational angle. 2.The drive apparatus of claim 1, wherein the dynamic gripping device isconfigured to simultaneously rotate and axially move the elongate memberwith respect to the support surface.
 3. The drive apparatus of claim 1,wherein the dynamic and static gripping devices are configured tocooperate to continuously grip the elongate member while simultaneouslymoving the elongate member axially with respect to the support surface.4. The drive apparatus of claim 1, wherein the dynamic and staticgripping devices are configured to cooperate to continuously grip theelongate member while simultaneously rotating the elongate member withrespect to the support surface.
 5. The drive apparatus of claim 1,wherein the elongate member is selected from the group consisting of acatheter sheath and a guide wire.
 6. The drive apparatus of claim 1,further comprising opposing pads, each defining an axial length, whereinthe opposing pads are positioned to open such that a length of theelongate member aligned generally parallel to the axial length of theopposing pads may be loaded into the drive apparatus between the openopposing pads from a direction generally perpendicular to the axiallength of the opposing pads.
 7. The drive apparatus of claim 6, whereinthe opposing pads include a convex contact surface.
 8. The driveapparatus of claim 1, wherein the drive apparatus is configured todetect a slipping of the elongate member with respect to a drivecommand.
 9. The drive apparatus of claim 1, wherein the drive apparatusis configured to track a user commanded movement with the dynamicgripping device.
 10. The drive apparatus of claim 1, wherein the driveapparatus is configured to track a user commanded movement by increasingmagnitude of a commanded movement.
 11. The drive apparatus of claim 1,further comprising a grip motor operatively coupled to the dynamicgripping device and configured to open the dynamic gripping device. 12.The drive apparatus of claim 11, further comprising a set of closingsprings coupled to the dynamic gripping device and configured to urgethe dynamic gripping device into a closed position absent a forceapplied by the grip motor.
 13. The drive apparatus of claim 11, furthercomprising a cam operatively coupled to, and driven by the grip motor,wherein the cam is configured to selectively actuate the dynamicgripping device and the static gripping device.
 14. The drive apparatusof claim 1, further comprising: a swing platform rotatable about an axisof rotation; and a rotation drive motor for controlling rotationalmovement of the swing platform, wherein the dynamic gripping device ispositioned on the swing platform so as to be rotatable with the swingplatform.
 15. The drive apparatus of claim 1, further comprising anaxial drive motor for driving axial movement of the dynamic grippingdevice.
 16. The drive apparatus of claim 1, further comprising a steriledrape positioned over the dynamic and static gripping devices.
 17. Thedrive apparatus of claim 16, further comprising multiple caps moldedinto the sterile drape and fitted to the dynamic and static grippingdevices to secure the sterile drape over the dynamic and static grippingdevices.
 18. A drive system, comprising: the drive apparatus of claim 1;and an instrument driver defining the support surface, wherein the driveapparatus is mounted on the instrument driver.
 19. The drive system ofclaim 18, wherein the instrument driver and drive apparatus arerobotically controlled.